The present invention relates to windrowers for cutting a crop material and depositing the cut crop material in rows on a field. More particularly, the invention relates to dual mode windrowers, that is, windrowers wherein the header or cutter head for cutting the crop may include either a disc cutter or a sickle bar cutter. At windrower start-up, the invention automatically determines whether the header has a disc or sickle bar cutter as the cutting means, and adjusts the header drive speed accordingly.
Some dual mode windrowers have heretofore been provided with a manually operated mode switch that an operator sets to a first state or a second state depending on whether a disc or a sickle bar cutter is to be used as the header cutting means. It is necessary for the windrower control system to know whether a disc or a sickle bar cutter is being used because the two types of cutters have different operating characteristics. For example, it takes significantly more operative power to obtain a given header speed when the header carries a disc cutter rather than a sickle bar. Thus, failure of the operator to properly set the mode switch when a new cutter is mounted on the header can result in poor fuel economy, unsatisfactory operation of the header during cutting, and possibly excessive wear and damage to the cutter.
An object of the present invention is to provide a control system for a dual mode windrower, the control system automatically determining whether the header carries a disc or a sickle bar cutter.
A further object of the invention is to provide a method and apparatus for automatically determining whether a windrower header is equipped with a disc or a sickle bar cutter.
Another object of the invention is to provide a method and apparatus for determining whether a windrower header is configured with a disc or a sickle bar and, from the determination, setting a configuration parameter for controlling drive power to the header.
At start-up, a drive signal for controlling header speed is increased until the header speed reaches a set point speed. When a sensor senses that the header has reached the set point speed, the magnitude of the drive signal that results in the set point speed is compared to upper and lower limits of a first range of signal magnitudes characteristic of the range of signal magnitudes normally required to drive the header at the set point speed when the header carries one type of cutter. If the drive signal magnitude does not fall within the first range of magnitudes, it is compared to upper and lower limits of a second range of signal magnitudes characteristic of the range of signal magnitudes normally required to drive the header at the set point speed when the header carries the other type of cutter. Header configuration data, determined from the comparisons, is stored in a memory and subsequently used by a microprocessor to derive drive signals for controlling the drive power to the header. The configuration data is used to select either first or second table of drive signal magnitudes, the tables being addressed by any set point speed value selected by an operator via a control panel. Thus, for any speed selected by the operator, the microprocessor generates a header drive signal having either a first or second magnitude depending on the determined configuration.
Although the invention permits elimination of any operator input regarding header configuration, it may be used in conjunction with an operator-controlled configuration data input means. In the latter case, the invention changes or overrides the operator input if the operator should input configuration data that does not agree with the actual header configuration.
Other objects and advantages of the invention, and its mode of operation will become obvious from consideration of the following description and accompanying drawings.